Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?

Lack of oxygen in muscles often leads to cramps among cricketers. This results due to:

$(a)$ Name the following:
$(i)$ Part where air is filtered by fine hair and mucus.
$(ii)$ Part which terminates in balloon-like structures.
$(iii)$ Balloon-like structures where exchange of gases takes place.
$(iv)$ Part which separates the chest cavity from the abdominal cavity.
$(b)$ Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms?

Why is the rate of breathing in aquatic organisms much faster than that seen in terrestrial organisms?

Explain the three pathways of breakdown of glucose in living organisms.

If a plant is releasing carbon dioxide and taking in oxygen during the day,does it mean that there is no photosynthesis occurring? Justify your answer.